Patients treated for leukemia and patients who have undergone bone marrow transplants have been exposed to various treatments that might alter bone metabolism. All of these treatments may induce gonadal failure and the subsequent hormonal deficiency may lead to osteoporosis. The cumulative toxicity of these various treatment modalities have the potential for alterations of the bone which may lead to osteopenia. This study seeks to determine the risk of osteroporosis with a view toward the early indentification of the process in patients at risk.